A semiconductor memory device that has a three-dimensional structure has been proposed in which a memory hole is formed in a stacked body in which multiple electrode layers are stacked, and a charge storage film and a semiconductor film are provided to extend in the stacking direction of the stacked body inside the memory hole. Such a semiconductor memory device includes multiple memory cells connected in series between a drain-side selection transistor and a source-side selection transistor. The electrode layers of the stacked body are used as word lines and selection gates. The stacked body includes a staircase structure portion at an end portion of the stacked body. The staircase structure portion includes multiple terraces provided every electrode layer. The terraces are portions where the electrode layers are drawn out to the outside from the stacked body. It is desirable to reduce the planar size of the staircase structure portion to downscale the semiconductor memory device.